(Bloomberg) — Scientists studying coral in a western
Pacific Ocean lagoon demonstrated that strong trade winds have
helped slow global warming for the past 14 years.
As they stir up the sea floor, the tropical winds are
pushing warm air into the ocean, cooling the atmosphere. The
Nature Geoscience study published today also shows that air
temperatures over the Pacific will rise faster when those winds
weaken.
Levels of manganese sediments in the coral samples that
coincide with wind intensity allowed researchers to date periods
of strong and weak winds back to the late 19th century more
accurately.
“This is part of a cycle that happens in the Pacific where
winds flip flop between really strong and really weak,” Diane
Thompson, a scientist at the National Center for Atmospheric
Research and one of the study’s authors, said in a telephone
interview. “When the winds are strong in the tropical Pacific,
as they are right now, you get more mixing of the heat into the
subsurface ocean, which leaves the surface ocean cooler and less
heat in the atmosphere.”
Coral can be studied similarly to tree rings, giving
researchers more data to help determine significant weather and
climate shifts, she said. The Pacific trade winds most recently
picked up speed in 2000.
The study doesn’t pinpoint when the next cycle of weaker
winds will start to cause temperatures to increase. The cycles
typically last two to three decades.
“We aren’t yet able to forecast those year-to-year
potential changes, but it’s critical that we’re able to
anticipate the rate of future warming,” Thompson said. “Like
trees, corals grow in yearly growth spans, so we can use the
chemistry of that.”
To contact the reporter on this story:
Justin Doom in New York at
jdoom1@bloomberg.net
To contact the editors responsible for this story:
Reed Landberg at
landberg@bloomberg.net
Carlos Caminada, Andrea Snyder